Focus-adjustment mechanism for lamps



Jan. 2l, 1930. F. L.. BAMFORD FOCUS ADJUSTMENT MECHANISM FOR LAMPS FiledSept. 50, 1925 55s/wc mfofo @an KZ. Bam/afa? Patented Jan. 2l, 1930UNITED STATES PATENT oFFIcE FRANK L. BAMFORD', OF DETROIT, MICHIGAN,ASSIGNOR TO C. M. HALL LAMP COM- PANY, OF DETROIT, MICHIGAN,

A CORPORATION OF MICHIGAN FOCUS-ADJUSTMENT MECHANISM FOR LAMPSApplication filed September 30, 1925.

The invention relates to vehicle head lights of that type in which theillumination is alternatively supplied by a pair of filaments in thesame bulb and off-set one from the other. Such constructions aredesigned to illuminate the road which is in the immediate foregroundwith the filament which is in the lower plane and greater distance withthe filament in the higher plane, but to accomplish this each filamentmust be positioned with great accuracy with respect to the axis of thereflector. There must also be provision for adjusting the filamentsaxially of the reflector for proper focusing.

It is the object of the present invention to obtain a simpleconstruction of adjusting mechanism for effecting both the focus and thelateral adjustment of the lamp.

Itis a further object to avoid any loose connection which might cause arattling or vibration of the lamp when in instant service.

With these objects in view the invention consists in the construction ashereinafter set forth;

In the drawings;

Figure l is a central longitudinal section through a lamp to which myimprovements are applied.

Figure 2 is a section on the line 2 2 of Figure l.

Figure 3 is a section on the line 3-3 of Figure 4:.

Figure 4 is a front elevation of the bushing as attached to thereflector.

Figure 5 is a perspective View of the bushinfr.

t is a lamp casing of any suitable form and B is the reflector mountedtherein. C is the bulb which is provided with a pair of filaments D, Darranged in parallel planes respectively above and below the centralaxis. The lamp bulb is mounted in a socket member E which extendsthrough a central aperture in the reflector and is provided with arearwardly extending shank F. This shank is engaged by a screw G passingthrough a slot in the rear wall of the casing A with its head H outsideof said casing. There is also a spring I arranged intermediate thecasing and the rear end of the shank F which forces Serial No. 59,660.

the socket forward to the position permitted by the adjustment of thescrew.

The construction as thus far described has been heretofore usld andprovides for the adjustment of the bulb axially of the re"- flector forthe purpose of focusing. It does not, however, accurately position thefilaments with respect to the lateral distance from the central axiswhich function is performed by the following construction;

J is a bushing member arranged within the aperture in the reflector andslidably receiving the socket member E. This bushing is pivotallyattached to the reflector preferably by providing the struck out lugs K,K on diametrically opposite sides thereof which engage recesses L, L inthe reflector B and in the horizontal and axial plane thereof and aspring M in a sleeve upon the bushing its rear end engaging a flange Nthereon and its forward end abutting against the rear face of thereflector. Thus the lugs K, K engaging the recesses L, L form rockerbearings or pivots for the bushing while the spring M holds these partsin engagement yieldably centering the bushing and preventing any rattle.To permit of assembling the parts, the reflector is apertured at O and Ofor the passage of the lugs K, K therethrough from the rear of thereflector, the spring M being compressed after which the bushing isrevolved to a quarter revolution to engage said lugs with the recesses Land L.

The pivotal connection between the bushing and the reflector justdescribed permits of rocking said bushing and the lamp socket containedtherein so as to tilt the bulb downward or upward within the reflector.To permit of this movement the screw G which connects the shank F withthe rear of the casing A is adjustable in the vertical slot F. I alsopreferably provide an adjusting mechanism which, as shown, comprises asliding bar P lying adjacent to the rear wall of the casing andapertured for the passage of the screw G. This slide also forms theabutment for the rear end of the spring I so that by movement of theslide the screw, spring and shank F will be carried therewith therebyeffecting rocking of the socket and lamp bulb. To

actuate the slide l? there is provided cam or eccentric Q which engagesthe bearing R, R on the slide and this: actuated l a rotary shank Slawine; a slotted head en the outside of the rear wall ot the canine',:raid shank haring?r a polygonal p v ortion to; en-

" *In H *11,11 4 1x11 l gaining: i 1c ea-n unie i 1 surionrctd iy a.spring S abutting` azgainst a collar U se b' a eotter nin U. Thistoi-nist: a iur-)le i i constructure to mauutzu'tizre and assemblecarrying; with it the eci-er.' Ch ep? shank F. lt ia tlieret( ile toquickly and easilj adinet the secure the desired ligglitiir;r elfe-etwhen each filament illuminated.

That l claim an in Xv infe i is:

l. In a lamp.. the combination with a reflector, a lamp bulb and aee-cliet ther:` paseing through an aperture in Said retlecf of a bushingtor s 'dab soelret pirotally engaging e, Silient means Sleeved on eengaging Said relleetor Said bueling trom nim and adjusting `ine-aneYfor roel in;r to adinet Said lamp bul b tran respect to the` axis otthe retletor.

2. In a la p, the combinati Y with a re- Hector` and a lamp soclietexto* through an aperture thereinf et a lr n in which said socketslidahl;v .fe :feo 'i' through the aperture in sai provided withda]uetrically hearings in an axial operatingr recezfssed beai 5;resilient moana 'tor holding engagement with each oil il 'attlinevv` andmeans 'i'or reehingf; and bushing.

3. n a lamp the combinlector. oi a lamp Soil-:et exit an aprrturethere?, i, meure, for lamp socket axially, a bueh fr in wh socket iselidably Secured `ileo paseine said aperture En the reflector@ u beingprovided with diauietriea, projecting luga 'wir rocl'zablj.7 cessedbeaiunm` if' sleeved on Laid i which the oppeeiie end i el. ln a lamp,the effi' Hector, el' a litiup ffofgiet uur aperture therein, abuehingjy Socket is slid ably secured also passingr through the auerturein the retrector, Said bushing having a radially outwardly extendingflange at its rear end an d beine; provided with struck out lues ondiametrically opposite sides ihereoY` and at its4 forward eli-fl, saidreflector be' j provided with Slots for the passage ot lugetherethrougrhand with recessed hearings Yter ei'igagring Said lugs when Said socket nen a partial revolution, and a Spring sleered on Said Seel-:et bearingat its rear end againet said flange and at its forward end afjfainst therear tace of the reflector.

ln a lamp the combination with a reflec- 'or, et a lamp socketextendingr through an aperture iereiu and provided with a riarwardlyeztenfliu Shank, ineaua ope able from outeide the cL` l) 'for adjustingSaid Shank a ne o/liet ai ally of the reflector, a bushing in which saidsocket if; alidably secured exdingr through and pivotall).7 engaging thelace of the raid reflector;y means; for yieldably t .,inine t le pivotale a en'ient ot Said huahing with Said reflector and meane operraidpivot.

6. ln a lamp, the coinlliuzition with a reflector, ol a lamp Socketpassing through an aperture therein and provided with a rearwardlyextendinev nl anl, a Screw for engrag ingy said Shank peering' through,an aperture in the rear Vall of the casing and provided witl'i onoperating; head outside the casing, a bushing in which seid socket isslidably .Cieeured i'iivotally engaging: Said reflector, a Slide ,vithinsaid caeinp; engaging Said Screw and :neat e operable Yfrom out 'de thecasing vtor adjuatinir Said Slide and through the medium ot aid Screwand Shank rocking Said Suchet a nd bushing.

7. In a lamp, the combination with a reflector., a lamp bulb and aSocket therelor pesaing throuejh an aperture in Said reflect 3r et abushing for Slidably receiving Said eoelet pivotally entrairinej Saidreliector, means for yieldably holding said bushing tree from movementon its pivote and for main- Viaininq the pivotal engagement of thebushinnV with the reflector ancL adjust-ing means ttor rocking Saidbushingr to adjust l@aid lamp bulb transversely with respect to the axisof the reflector.

S. In a lamp, the combination with a reflector, of a lamp socketpivotally engaging said reflector, and provided with av rearwardlyextending shank. mean@ paesing through a elet in the rear wa l ot thecasingand engagsaid shank for ad iuatiner the same and d Socket axially,a slide inside Said casing jacent to the rear Vall thereot engaging:raid adjusting' meane, a cam member for actuatinl said slide to rocksaid socket on its pivot, and means operable from outside the casing foractuating said cam.

9. In a lamp, the combination with a re- Hector, of a lamp socketpassing through an aperture therein and provided with a rearwardlyextending shank, a bushing in which said socket is slidably securedpivotally engaging said reflector, a screw passing through a slot in therear wall of the casing and engaging said shank to adjust the sameaxially of the refiector, a slide inside said casing adjacent to therear wall thereof engaging said screw, a spring surrounding said screwbearing against said slide and said shank, a cam for engaging said slideto actuate the same, and a rotary shank for said cam passing through therear Wall of the casing and operable to rock said bushing and socket.

10. In a lamp, the combination with a housing and a reflector therein,of a lamp socket rockably mounted within said housing, a slide forrocking said socket, a cam for actuating said slide and a shank foractuating said cam, said shank having a slotted head outside saidhousing, a polygonal portion within said housing engaging said cam, aspring sleeved on said polygonal portion for exerting a resilientpresure on said cam to prevent rattling of the same, a collar on saidshank forming abutment for said spring and a cotter pin for retainingsaid collar on the shank.

11. In a lamp, the combination with a casing, of a reflector within thecasing, the said reflector being provided with an aperture, a lampsocket., means for pivotally and slidably mounting the lamp socket inthe aper ture in the reflector, a shank extending rearwardly from thelamp socket, means passing through a slot in the rear wall of the casingand engaging said shank for adjusting the socket axially, resilientmeans for urging the said shank and socket forwardly, and a slide withinthe casing and engaging the said adjusting means for rocking the saidadjusting means, shank, and lamp socket.

In testimony whereof I aiiix my signature.

FRANK L. BAMFORD.

